Railway traffic controlling apparatus



May 23, .1939. E. M. ALLEN RAILWAY TRAFFIC CONTROLLING APPARATUS 3 Sheets-Sheet 1 Original Filed Jan. 22, 1935 F4 12 A 1151512 may INVENTOR Earl 11!. Allen.

H15 ATTORNEY y 3, 193.9- .E. M, ALLEN 2,159,515

RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed Jan. 22, 1935 3 Sheets-Sheet 2 l I l a i l AITPZ 22 $2 INVENTOR Earl 11!. Allen.

BY 2 1 K 5 1-115 ATTORNEY May 23, 1939. E. M. ALLEN RAILWAY TRAFFIC CONTROLLING APPARATUS Original Filed Jan. 22; 1935 3 Sheets-Sheet 5 AST swsa 51:51: 391 201 B a "1,, m

5 u w H M m Mm MS Cfl4 u INVENTOR Earl M .All e12.

BY Q/XW HIS ATTORNEY Patented May 23, 1939 UNITED STATES PATENT OFFECE RAILWAY TRAFFIC CONTROLLING APPARATUS Pa., a corporation of Pennsylvania Application January 22, 1935, Serial No. 2,845 Renewed January 2, 1937 28 Claims.

My invention relates in general to railway traffic controlling apparatus for governing traffic over a single track stretch of railway having one or more switches associated therewith for enabling the routing of traffic over divergent routes, and more particularly it relates to that class of apparatus whereby the movements of the switches and signals associated therewith are controlled from a remote point, such, for example, as a central oflice.

In systems where the movements of a railway switch and its associated signals are controlled from a remote point, it is customary to provide approach locking circuits. One feature of my invention has to do with the provision of means which exactly checks that approach and all route locking has been applied before a signal can be cleared.

I further provide means for picking up the approach locking relay of stick and non-stick signal circuits without requiring the leverman, centralized trafiic or control operator, a the case may be, to release the signal control relay at the time the train occupies the-approach locking release section.

Another feature of my invention has to do with the arrangement of certain of the circuits in a manner which provides stop signal protection against the false picking up of the stop signal repeater relay should its control wire become falsely energized by virtue of a positive ground,

cross or similar failure.

A still further feature of my invention comprises the provision of means for insuring the integrity of the track circuit shunt between the home and distant signal after a train has passed the distant signal, by so arranging the circuits that any loss of shunt cannot modify the pick-up circuits of the approach or route locking relays to thus effect the release of the approach or route locking, except when a train passes the home signal and releases approach locking in. the regular manner or through operation of a time element relay. Further features of my invention will appear from time to time a the specification progresses.

The apparatus of my invention is an improvement over that disclosed in the copending applications Serial No. 416,061, filed December 23, 1929,

by Howard A. Thompson for Multiple control apparatus; Serial No. 695,294, filed October 26, 1933, by Allen and Thompson for Interlocking control apparatus; and Serial No. 14,868, filed April 5, 1935 by Allen and Thompson for Interlocking control apparatus. I

I have illustrated my invention in three sheets of drawings comprising Figs. l 1 and 1. These figures, when placed side by side with Fig. 1 to the left of Fig. 1 Fig. 1 to the right of Fig. 1 and with the corresponding track rails in alignment, form a diagrammatic view of the apparatus and circuits embodying my invention when applied to a stretch of track over which traflic normally moves from left to right, but over which trafiic sometimes moves in the reverse direction. Ihe track also has a number of associated railway switches via which traflic may be routed. The switches employed are designated by the numerals l, 3 and 5 and may be operated by any standard type of switch machines, not shown, but which are well known and may be controlled in any desired known manner. In the present instance, the operation of the switch machines of switches I, 3 and 5 is assumed to be by switch control relays under control of operator controlled relays to be referred to later.

By means of insulated joints llll the track rails I02 and I63 are divided into track sections BIT, AIT, IT, 3T, 5T, AS'I, and 135T, respectively. Each track section is provided with a customary track circuit which includes a track battery and a track relay in a manner readily understood from the drawings. A two-position semi-automatic non-stick wayside signal REA is employed in governing the movement of eastbound trains over the main track of the stretch-while the reference character D4 designates a three-position fully automatic distant signal for RGA. The signal R43 is of the two-position manual call-on type and is employed to permit trains to enter the stretch of track controlled by the signal R4A, while such track is occupied and also to direct eastbound traffic, over the alternative or secondary routes, namely over switch 3 or 5 reversed. The signal R40, associated with the sidetrack of switch I, is also of the manual type and permits eastbound trains to enter the main line track both for train movements over the main line and also for movements via switches 3 and 5 reversed.

The signal L4A governs westbound trafiic movements over the main track and over a diverging route via switch I reversed and functions as a manual signal for movements exclusively over the main track and as a semi-automatic stick signal when cleared for movements over the diverging route. The signals L lB and L4G are of the same type as BAG and govern the trafiic movements .to the main line from the switches 3 and 5 reversed, respectively. The signals employed may be of any well known type, but as here shown, are color light signals of the Searchlight type, such as disclosed in the United States Reissue Patent No. 14,940, granted to E. J. Blake.

In order to simplify the figures somewhat and to make them easier to understand, I have, in a number of instances, placed circuit controlling contacts and armatures in locations that are not adjacent to the relays that control them, In all such instances these contacts or armatures are designated by the reference character of the relay to which they belong, and have an additional numerical designation. The contacts 29 of Fig. 1 for instance, having associated there'- with the reference character IESR are controlled by relay IESR of Fig. 1 and these contacts are shown in their normal or closed position.

In Fig. 1 are shown circuit controllers 216, 21 and 28 which are operated by switch I. Each controller occupies its upper position, indicated by the solid line, when the switch is set for the main track; while each controller occupies the down position, indicated by the dotted line, when switch I is set for traiiic movements between the main track and the siding. The switch control relay IW for switch I is a direct current polarized relay having polar armatures that remain in the position to which they have moved when last energized. This relay IW, when energized with current of normal polarity, moves its polar armatures to a normal position that selects the operating circuit (not shown) for the switch machine (not shown) of switch I and this results in switch I being positioned for traffic on the main line. With current of reverse polarity supplied to the relay IW, then its polar armature is moved to a reverse position that selects the operating circuit for the switch machine that result in switch I being positioned for traific between the main line and the siding. In the present drawings, the normal position of the polar armatures of relay IW,

and of all other polar relays, is left-hand, and the reverse position is the right-hand position, that is opposite from that shown.

The switch control relay IW is controlled by remote controlled relays IX and I Y. With normal relay IX selected by the operator and its armatures 48 and 49 raised, current is supplied to the relay IW by a circuit extending from the positive terminal B of any suitable current source, not shown, but the opposite terminals of which are herein designated B and C, respectively, armature 46 and its back contact, the front contact and armature 48, contacts 20, I9 and 29 of relays IESR, IWSR, and ITR, respectively, the winding of relay IW, armature 4t and its front contact, and the back contact and armature 4? to the negative terminal C. The polarity of current thus supplied moves the polar armatures of relay IW to the left-hand side and thus brings about the normal positioning of the switch. With the operator selecting the reverse relay IY and with relay IX released, it will be apparent that the flow of current to relay IW is in the reverse direction to that formerly traced and, accordingly, the polar armatures will be reversed to the right-hand position with the result that the switch I is set for traflic between the siding and the main line.

The switch controlled relay IKR is controlled jointly by the switch I and the relay IW. With the switch set in the normal position, and relay IW also in its normal position, the circuit of relay IKR extends from the positive terminal B, controller '28, winding of relay .IKR, normal contact and armature I 04, through the controller 26 to the negative terminal C. With the switch I and relay I W in their reverse position the circuit for relay I KR extends from the positive terminal B through controller 21, the reverse contact and armature I04, winding of relay IKR and the controller 28 to the negative terminal C. The switch control indication relay IKR when energized controls associated normal or reverse switch position indication repeating relays INP and IRP over neutral contacts 53 and the polar armature 54. It is to be understood that the circuits which ordinarily extend between the windings of the switch controlled relays SKR and SKR of switches 3 and 5 and the circuit controllers of these switches and relays associated therewith corresponding to IX and IY, all of which are ordinarily provided, have been omitted from the drawlugs for the sake of simplicity. This equipment and associated circuits, however, is quite similar to that shown for controllng relays I W and IKR and will, therefore, be readily understood.

The direction of trafiic over the stretch and its various branches is selected by directional control relays R4I-IS and L II-IS, respectively, which may be directly controlled from a remote point by a leverman or by codes selectively transmitted over a centralized trafiic control system in exactly the same manner as are the relays IX and IY.

The various switches, signals and relays disclosed are shown in their normal positions, with the R4 signal repeating relay R ERGP, special function relays AITPZ and ITS, the approach locking relays IESR and 5WSR and the route locking relays SESR, BESR, and IWSR. picked up.

The pick-up circuit for relay RdRGP extends from the positive terminal B through contacts 8, 9, 6, I, 2 and 4 of the signal mechanisms R ECM, RAAM, RABM of signals R40, R4A, and B4B, respectively, through contacts of a distant relay D4RI-IP also picked up over an obvious circuit, contacts 60 of relay RAHS and the winding of relay R IRGP to the negative terminal C.

The relay IESR, is being held energized over an obvious stick circuit after having been picked up over a circuit including the positive terminal B, contacts 61, over one of the three obvous possible multiple paths to the'contacts B2 and through the winding of relay IESR to the negative terminal c.

The relay SWSR is being held energized over a stick circuit extending from the positive terminal B, through contacts I06, 98, H91, 99, N18 and I III! of the mechanisms of L iCM, LAAM and LGBM of signals L40, L4A and L4B, respectively, contacts H of relay L4HS, armature 55 of relay SWSR and its front contact and the winding of relay 5WSR to the negative terminal C. This relay was initially picked up over a circuit similar to that traced, but including one of the four other obvious multiple paths extending between contacts ll and the relay winding. The pick-up and stick circuits of each of the relays AITPZ, ITS, SESR, SESR and IWSR are closed and are so obvious as to make the tracing of these circuits unnecessary.

It is believed that an understanding of the invention can best be obtained by describing the armature 69 interrupts a point in an operating circuit common to the L4 signals and closes a point in a circuit common to the R4 signals. The relay RARGP, upon restoring, at contacts 51 interrupts the circuit of the approach locking relay of relay SESR, the back contact and armature l3 of relay L4HS, neutral contacts 94 of relay 5KR, the normal contact and polar armature 93 of relay 3KR and its neutral contacts 9| I the neutral contacts H9 of relay IKR, and armature 69 of relay R4I-IS and its front contact where the circuit divides, one branch extending via contacts 4 of relay IESR, contacts 58 of relay R4RGP, the polar armature 86 and normal contact of relay IKR, armature 66 and back contact of relay 4US, through contacts 14-19 of relays 5NP, 3NP, I'IR, 3TB, 5TR. and A5TR, respectively, and through the winding 80 of signal R4A to the negative terminal C. The signal R4A accordingly changes from stop to proceed, and in so doing, at contact 6 of its operating mechanism R4AM, opens a second point in the circuit of relay R4RGP, and closes an obvious circuit through the distant relay 4DR. The relay 4DR in lifting its armatures 43 and 44 reverses the direction of current flow through the winding 45 of signal D4 which accordingly moves to clear, and at contacts 82 of its mechanism D4M opens the circuit of relay D4RHP.

The other branch of the circuit closed by contacts 52 of relay 5ESR extends via the front contact and armature 95 of relay A5TR, through the back contact and armature 65 of relay 4US and through the winding of slow operating and slow releasing relay R4HSP to the negative terminal 0. After a slight delay relay R4HSP operates and at its contacts 63 places a shunt around the now open contacts 60 of relay R4HS. The relay R4RGP remains deenergized, however, since its circuit is now open at contacts 6 of the R4A signal mechanism R4AM as already explained, and also at the contacts on the D4RHP relay which is controlled from contacts 82 of mechanism D4M.

If there is stray operating potential on the conductor extending between the contacts of relay D4RHP and contacts 60 of relay R4HS, the relay R4RGP will be again picked up as soon as the contacts 63 of relay R4HSP close, and will accordingly, at contacts 68 again interrupt the circuit of the cleared signal and such signal will immediately return to stop. On the other hand, it will be apparent that should a cross with the conductor leading to terminal C become applied to the conductor extending from the relay R4RGP and shunt the normal current therefrom the relay R4RGP will deenergize, but none of the R signals will be cleared unless the directional relay R4I-IS has been picked up to clear one of such signals.

Aside from the foregoing protective features of the circuits I employ, before the signal R4A can be cleared; all track relays of the stretch must be energized, indicating the unoccupied condition of the stretch; the normal position switch repeating relays 3NP and 5NP must be energized, thereby repeating the normal position of these switches; indication relays IKR and 3KR must be energized and have their polar armatures in their normal position, thereby checking the position of the switches as well as that such position agrees with that of its switch control relay; relay 5KR must be energized to check that switch 5 is in a position in agreement with its control relay; the directional control relay L4HS must be deenergized, thereby checking against any attempt to clear the L4 signals; and finally route locking relay 5ESR must be deenergized. Now since the deenergization of relay 5ESR is dependent on the release of relay 3ESR, and since the release of relay 3ESR is dependent on the release of relay IESR, and further, since the release of IESR is assured by the release of relay R4RGP by relay R4HS, assurance is had that all of these relays will be deenergized at the time signal R4A is cleared. It will be observed from the control circuit of switch control relay l W that this relay cannot be operated to move the switch while contacts 20 of relay IESR, are open. In like manner, the control relays 3W and 5W of switches 3 and 5 are disabled by contacts 2M and 202 of their respective 3ESR and SESR route locking relays, when deenergized.

It will now be assumed that signal R4A has been cleared and that an eastbound train enters the approach section BIT. When this occurs track relay BITR restores and at its contacts 24 opens a point in the pick-up circuit for approach locking relay IESR. As the train enters approach section AI T the track relay AITR restores and at its contacts 96 opens the pick-up and stick circuits of relay AITPZ. The pick-up circuit of this relay is now also open at contacts N6 of relay IESR. Relay AITPZ therefore restores, and at contacts 22 opens a second point in the pick-up circuit of relay IESR. Ordinarily, the release of relay AITPZ is of no consequence, because, with the signal R4A at "proceed the pick-up circuit of relay IESR is held open at contacts 61 of relay RQ-RGP.

. If, however, the relay RAHS is released while there is a train in approach section AIT, the relay RAHS, at armature 69 opens the circuit of signal R4A. This signal accordingly returns to stop and at its contacts 6 reestablishes the circuit through relay R4RGP, relay D4RHP having closed its contacts on entry of the train into section AIT. Under the foregoing circumstances, should a loss of shunt occur causing contacts 96 of relay AITR to momentarily close while the train is in section AIT, relay AITPZ serves to prevent the possibility of the loss of the approach locking for the reason that contacts 22 of relay AITPZ are open and cannot be closed until the train is actually in the detector section !T, as the pickup circuit of relay AITPZ includes the now open contacts H6 of the relay IESR.

When, however, the circuit of signal R4A is interrupted and relay R4RGP is again picked up, this relay, at contacts 6?, closes a circuit for the usual time element relay 4TER, via armature I I2 of relay USSR and its back contact. After the usual operating time of relay 4TER this relay at contacts 4| closes an obvious circuit through the relay IESR. If the train is still in the approach section, release of approach locking is effective and switch I may be moved by operating relay iW. Obviously, the operation of this relay is prevented by contacts 29 of track relay ITR being open if the train has by this time entered the detector section IT.

In case signal R4A is cleared for an approaching train and then returned to stop after such train enters section MT and the train then backs out of the stretch the picking up of the approach 5; locking relay IESR will also only occur through operation of the time element relay 4TER. This is true because relay AITR on picking up can not complete the pick-up circuit for relay AITPZ because relay ITR has not been deenergized to reclose the pick-up circuit of relay IESR. Since the L signal network includes contacts I I5 of relay lEsR the foregoing timing arrangement prevents the operator from being able to, immediately after returning the R signal to stop, clear one of the L signals before the train has had time to enter section IT or back out of section AIT.

For the time being it will be assumed that signal R4A has been cleared, a train has entered 20 section AIT, that accordingly relays AITR and AlTPZ have become deenergized as already described, and that relay RAHS remains picked up. When the train enters section IT, track relay lTR releases and at contacts 16 opens the circuit traced to the winding 80 of signalR4A. The Signal R4A accordingly goes to stop and at contacts 6 reestablishes a circuit through relay RGRGP. This circuit is the same as that originally existing except that it now includes contacts 63 of relay RAHSP instead of contacts 60 of relay R4HS.

The relay RdRGP, upon picking up, at contacts 68 opens a second point in the operating circuit of signal FHA, and at contacts 61 closes a pick- 11;: circuit for relay IESR including contacts 23 of relay ITR and 62 of relay RAHSP. The relay IESR on picking up, at armature I I2 prevents the operation of relay 4TER and establishes a stick circuit for itself independent of the track relay ITR. The relay IESR. also at contacts H6 reestablishes the circuit through relay AI'IPZ and this latter relay accordingly again picks up. Finally, the relay IESR, at contacts I I3, closes a'point in the pick-up circuit of relay 3ESR, but this circuit is now held open by contacts 35 of track relay ITR.

When the train enters section 3T relay 3TB, releases, at contacts ll opens another point in the circuit of signal R4A, and at contacts 34 opens a 2 second point in the pick-up circuit of relay 3ESR. The relay 3TB also, at contacts 59, opens a point in the pick-up circuit of relay IWSR, but without effect in View of the already established stick circuit in shunt of contacts 59.

When the train clears section IT track relay ITR again picks up, at contacts 16 closes a point in the circuit of signal BAA, closes a second point in the pick-up circuit of relay lWSR, at contacts Ill, and at contacts 23 opens the pick-up circuit of relay IESR. The relay ITR also, at contacts 29, again renders the switch control relay IW operable to change the position of switch I,

When the train enters section 5T the track relay 5TB restores, at contacts 18 opens a point in the circuit of signal RAA, at contacts 58 opens another point in the pick-up circuit of relay IWSR, and at contacts 36 opens a second point in the pick-up circuit of relay SESR. The relay A5TR also, at armature 95, opens the initial F circuit of relay Rdl-ISP and closes a stick circuit for this relay including its contacts 64 and contacts SI of relay R4I-IS.

When the train clears section 3T, the track relay 3TB, again picks up, at contacts 11 closes a point in the circuit of signal R4A, at contacts 59 recloses a point in the pick-up circuit of energized relay IWSR, at contacts 9| opens a point in a pick-up circuit of relay EWSR, and finally, at contacts 34, completes the pick-up circuit through relay 3ESR. The relay 3ESR on picking up, at contacts 3|, reestablishes its stick circuit and at contacts 33 closes a point in the pick-up circuit of relay EESR. The relay 3ESR, at contacts ZOI renders the control relay 3W of switch 3 operable to change the position of switch 3.

When the train clears section 5T the relay 5TB, again picks up, at contacts 18 recloses a point in the circuit of signal RAA, at contacts 89 opens a point in a pick-up circuit of energized relay EWSR, at contacts 58closes the pick-up current of energized relay I WSR, and at contacts 36 completes the pick-up circuit of relay SESR. The relay EESR on picking up, at contacts 5| closes one point in its stick circuit, and at contacts 52 interrupts the circuit originally closed to supply positive potential to signal RAA and relay R4HSP. With the track relay 5TB, and route locking relay SESR picked up, the operating circuit for relay 5W is prepared at contacts 29! .and 292, so that it may be operated to effect movement of switch 5 in the same manner that such a circuit is prepared for control relay IW of switch I, or relay 3W of switch 3.

When the train clears section A5T its track relay A5TR again picks up and at its contacts 19 recloses a point in the circuit of signal EL SA. The signal does not yet clear, however, as its circuit is still open at contacts 68 ofrelay R lRGP, H4 of relay IESR and 52 of relay EESR. The relay AliTR, at armature 95 interrupts the stick circuit of relay R lHSP and again closes a point in the pick-up circuit of this relay. After a slight interval relay R lHSP restores and at contacts 64 opens a second point in its stick circuit. The relay RAHSP also, at contacts 63, interrupts the circuit of relay R4RGP, which accordingly restores. The sequence of circuit changes which follow are identical to those previously described, as following the restoration of relay R lRGP by the picking up of relay R lI-IS. It will be obvious, therefore, that the signal BAA will again automatically clear, and that the described; cycle will be repeated as each following train or vehicle clears section A5T so long as the relay RAHS remains picked up.

If the relay R4HS is restored any time after a train enters the detector section IT and before such train enters section A5TR the described operations will be modified somewhat. In such an instance when the train enters section A5T and relay A5TR releases, the pick-up circuit of relay R lHSP will be interrupted by armature 95 as: previously described, but no stick circuit for this relay can be completed owing to contacts iii of relay RAHS being open. Therefore, after a slight interval, relay RAHSP releases and opens contacts 63. The opening of these contacts is ineffective at this time, however, owing to contacts 6E! of relay R4HS now being closed.

When the train clears section Ai'eT its track relay ASTR again picks up and at its contacts l9 recloses a point in the circuit of signal RQA. The signal does not clear, however, as its circuit is now held open at contacts E8 of relay RGRGP, I [4 of relay IESR, at the front contact and armature 69 of relay R lHS, and at the contacts 52 of relay SESR. Since relay RAHSP is already released the picking up of armature 95 is without effect at this time and the circuits are now in exactly the condition they were prior to the picking up of relay R4I-IS. It will be seen, therefore, that with the arrangements herein provided, once the usual route has been set up for traflic in the normal direction over the stretch and the signal for such route cleared, the release of the directional control relay need not be efiected until a different route is to be set up.

If the relay RfiI-IS is picked up at a time that switch 3 is in its reverse position, the operations which follow will be modified, as it will be apparent that under these circumstances the normal switch indication relay 3NP will be deenergized and reverse indication relay 3R1? will be picked up for reasons which will be obvious from an inspection of the drawings. With relay 3R? picked up contacts 31 of this relay place a shunt about contacts 33 of relay 3ESR, and therefore, when 3ESR restores, following the picking up of relay FAT-IS, and the release of relays R4RGP and IESR, it does not in this instance interrupt the circuit of relay EESR. It will be obvious,

therefore, that relay 5ESR does not release as the route set up does not involve section ET and therefore locking of the switch of this section is unnecessary and may be undesirable.

The relay SESR now, however, extends positive potential from contacts 56 of relay EWSR, through contacts 32 of relay 3ESR, the back contact and armature 12 of relay L4HS, the reverse polar contact and armature 93 of relay 3KR, the neutral contacts 9 of this relay, neutral contacts I I9 of relay IKR, armature 69 of relay RAHS and its front contact, contacts i M of relay IESR, 68 of relay RARGP, polar armature 86 of relay IKR and its normal contact, contacts 82 of relay 3RP and through the winding 8| of signal RAB to the negative terminal C. The positive potential applied to this circuit also extends over the previously traced branch circuit including relay RAHSP.

The signal R413 now changes to proceed indication and at contacts 4 of its mechanism RABM interrupts a second point in the circuit of relay R iRGP in the same manner as did the contacts 6 when signal R iA cleared. An instant later the slow acting relay RAHSP picks up, but operation of its contacts 63 is of no utility in the present instance as will be brought out subsequently. The signal RAB as herein employed simply advises an engineer that the train may enter the stretch at slow speed. This signal is not placed under the control of the track relays and therefore maintains its proceed indication after the train enters the stretch.

When the train enters section IT the track relay [TR releases, at contacts 29 opens a second point in the circuit of switch control relay IW,

and at contacts 23 closes a point in the pick-up circuit of relay IESR. Since the operating circuit of signal B4B does not include contacts of track relay ITR the circuit of this signal is not interrupted when the train enters the section. Therefore the contact mechanism R lBM of signal B4B does not establish a circuit through the relay R IRGP when the section is entered. The

relay IESR consequently does not pick up, and the control circuit for moving switch I is held open at contacts 29 of relay ITR and also at contacts 20 of relay IESR.

When the train enters section 3T the track relay 3TB. in releasing, at contacts 29!) opens another point in the circuit of relay 3W, at contacts 34 opens another point in the pick-up circuit of relay 3ESR in'addition to points in this cirwill sufiice.

and N3 of relay IESR. It will therefore be obvious that the control circuit for switch 3 cannot be closed while the train occupies section 3.

The operator can obtain control of switches l and 3 as soon as the train clears their respective sections IT and ST by releasing the relay RAHS. When relay RAHS is released, armature 69 opens the circuit previously extended to relay R4HSP and to the winding 8| of signal RAB. The signal now returns to stop and at contacts 4 of its mechanism R4BM reestablishes a circuit through relay R4RGP. The relay RARGP at contacts 61 now completes the pick-up circuit of relay IESR. The relay IESR, on operating, at armature H2 prevents the operation of relay 4TER at this time. An instant later relay RAI-ISP releases and at its contacts 62 reopens the pickup circuit of relay IESR. If, after clearing a signal such as RAB, relay RAHS is not released until after the train has cleared the detector section IT, relay R4RGP, instead of at contacts 61 immediately completing the circuit of relay IESR via contacts 23 of relay ITR, at contacts 31 first completes the circuit of time element relay ATER for a sufficient time to enable it to operate. The relay 4TER then, at contacts 3| completes a circuit through relay IESR to pick it up.

When the train clears section iT the track relay ITR again picks up and at its contacts 29 again prepares the circuit of relay lW to enable the operator to again move the switch.

When the train passes onto the switch 3 and clear of track section 3T, the track relay 3TB, again picks up and at contacts 36 closes the pickup circuit of relay 3ESR. The relay 3ESR in picking up, by closure of its contacts 23!, again returns the control of switch 3 to the operator.

If the switch 5 is the one reversed, the operations are quite similar and it is believed a brief pointing out of the differences in the operation With the switch 5 reversed, it will be obvious that its switch indication relay 5KR will have its armature moved to the right, its reverse position, and that its associated reverse indication relay ERP will be picked up instead of its fiNP relay. The signal RAB is employed for either of the foregoing routes. With switch 5 reversed and switch 3 in its normal position, the contacts 31 of relay 3R? are open and the SESR, relay is released to lock switch 3 in the same manner as when the RLlA signal is cleared.

Likewise, the positive potential employed in energizing winding 8| of signal RAB and relay R4HSP passes over substantially the same path as when signal RAA was cleared, the only difference being that, with contacts 16 of relay 5N? open, current cannot flow to the winding of signal RAA, but now flows via contacts 92 of relay 5RP and through the winding 8! of R313 to the negative terminal C. When the switch 5 is in its reverse position and signal R iB has been set at proceed, a train entering the stretch and passing on into section 3T clear of section lT brings about operations identical to those occurring when switch 3 was reversed.

When the train enters section 5T the associated track relay 5TB releases and at contacts 23!, corresponding to contacts 29 of relay ITR, opens a second point in the control circuit of the switch 5, this circuit being already open at contacts 252 of relay BESR, corresponding to contacts 20 of relay 1 ESR. The train in clearing section 3T effects circuit changes identical to those occurring when section 3T is cleared by a train leaving the section Via switch 3. When the train has cleared 7 5 section ET, the track relay 5TB. at contacts 29I again closes one of the open points in the control circuit of switch 5, but since relay SESR has not yet been picked up, the switch remains locked from control by the operator. Control of switches I, 3 and 5 can only be regained by releasing relay RQI-IS which will, in releasing, bring about the interruption of the circuit to signal B4B and effect the picking up of approach and route locking relays EESR, and 3ESR in the manner previously described. Relay SESR on picking up at contacts 33 closes the pick-up circuit through relay SESR. With these relays all energized, control of the respective switches is returned to the operator.

It will be seen from the foregoing that if relay RAI-IS is restored while the train is in section ET, the circuit to winding 8| of signal RdB and to the relay RAHSP will be interrupted at the front contact and armature 69 of relay R il-IS and the energization of relay lESR will be brought about in the same manner as when relay RHS is released with the train H and clear of section 3T, or 5T, as the case may be.

Under these circumstances, contacts 29 of relay ITR prevent completion of the control circuit of switch I, while contacts 35 of relay ITR prevent the picking up of relay SESR. However, as soon as the train clears section lT, the control circuit for switch I is available. Likewise, when the train clears section 3T, the pick-up circuit for relay 3ESR is closed at contacts 34 of relay 3TB. The relay QESR in picking up at contacts Zill restores control of the switch 3 to the operator. Whether the section 3T is cleared by the train entering a siding via switch 3 or by passing on into section 5T is obviously immaterial. If the train has been routed via switch 5 it will be obvious that contact 2B2 of relay liESR and contacts 25 of relay 5TB, prevent the operator from obtaining control of switch 5 until the train has cleared section 5T.

There may be times during which there is already a train in the stretch which has entered under clearance of signal BAA, and that the operator desires to give a following train permission to also enter the stretch. Under these circumstances he may do so by setting the signal R53 to proceed. This can be accomplished under these circumstances only by first releasing relay BAHS, picking up call-on signal control relay AUS and by then again picking up the relay Rel-IS.

The relay B ll-IS, on releasing, at armature 69 interrupts the circuit of relay R4HSP. Relay RQHSP, on releasing, at contacts 63 now interrupts the circuit of relay RHRGP, but BARGP stays up because contacts 59 of relay B l-HS are now closed. Now, when relay iUS is picked up, armature $5 excludes armature 95 of track relay ABTR from the operating circuit of relay R lHSP, and armature 66 at its back contact opens a further point in the circuit of signal FAA and at its front contact closes a point in the circuit of signal RAB. Now when the relay R lI-IS is again picked up, armature B9 completes circuits to relay R lI-ISP and to the winding 8| of signal RAB, respectively. As hereinbefore explained, signal RAB interrupts a second point in the circuit of relay RGRGP before relay RAHSP closes contacts 63 and therefore the relay R lRGP, and the approach and route locking relays lESR, 3ESR and EESR will deenergize and remain deenergized until the call-on signal resumes its stop indication. As soon as a train enters the stretch the operator ordinarily restores relay 4US. When this takes place the relay 4US" at armature 65 again places the picked up relay RAHSP under the joint control of track relay A5'I'R and R lI-IS. The relay 4US, at its armature 66 opens the circuit of winding 8| of signal RAB so that it will resume its stop indication, and again closes a point in the circuit of winding of signal R4A. Signal B4B, in returning to its stop position, at contacts i again completes the circuit of relay R lRGP.

It will now be recognized that the circuits and relays of the stretch are in the same condition as described when a train was proceeding through the stretch after entering it under clearance of signal RAA and therefore when both trains have cleared the stretch signal RA will again clear if relay R SHS has not in the meantime been again restored, as under these conditions both the stick and pick-up circuits of relay RfiHSP will be open, and relay RAHSP will accordingly release to effect the release of relay R4RGP and the consequent release of relays lESR, 3ESR and EESR as is necessary to the completion of the circuit of signal R4A.

It will be noted that the following train need not necessarily follow the first train through the stretch, for, as previously explained, when the first train clears section 3T the 3ESR relay is picked up and the position of switch 3 may be reversed thereafter and any time prior to the entry of the following train into section lT.

It will now be assumed that the operator picks up relay RAHS for the purpose of clearing signal R40 to permit a train to enter the stretch via switch I reversed. It will be obvious that, before this can be done, switch I must be operated to its reverse position and that such reversal must be checked by the movement of the polar armature 86 of the associated switch indication relay IKR to its reverse position. One or the other of the switches 3 or 5 may, of course, also be reversed at this time if the train is to follow one of the secondary routes. With switch I in its reverse position, relay RAHS, on picking up, effects circuit changes as hereinbefore described in connection with the clearance of signals RAA and RAB except that since armature 86 of relay IKR is now in its reverse position the signal circuit completed includes conductor 8? and the winding 88 of signal R40. The signal RAG, in moving to proceed position, at

contacts 9 interrupts a second point in the circuit of relay R4RGP in the same manner as did signal B5B on clearing.

It will be observed that the circuit of the R40 signal winding 88 is quite similar to that of winding 8! of signal R lB in that neither of these circuits include contacts of any of the track relays of the stretch. It follows, therefore, that once the switches have been set for the route desired and the signal R40 cleared, such signal will remain cleared until its circuit is interrupted by the release of relay RAHS. The picking up of the relay IESR following the release of relay R lI-IS to return signal R40 to stop is accomplished in the same manner as when the relay RAHS is released to return signal RAB to stop.

Attention is now directed to the control of train movements over the stretch in the opposite or westbound direction, against the normal direction of trafic. For such movements dwarf signals MA, MB and L4G, permitting westward movement of traflic, only under caution signal indication, is provided for. In order to illustrate that the present invention can be employed in conjunction with semi-automatic stick signals,

' locking these switches against operation.

'as well as in circuit arrangements employing semi-automatic non-stick signals, such as R IA, the operating winding 84 of signal L IA is included in a circuit controlled by track relays ITR, 3TB, and TB when switch I is in its reverse position, but shunted by contacts of the normal indication repeating relay INP when the switch I is in its normal position, thereby changing the character of signal L IA from the manual to the semi-automatic stick type when such signal is cleared after the reversal 'of switch I. The windings 82 and 85, respectively, of signals LAB and L4G are included in operating circuits generally similar to those of signals B4B and R40 in that they do not include contacts of the track relays. The signals L4B and L4G, therefore, are manually controlled at all times.

It will now be assumed that, with switch I in its normal position, the operator picks up the control relay LfiES to clear signal L4A to permit a westbound train to enter the stretch. Relay L4I-IS, in picking up, at contacts II opens the stick and pick-up circuits of the approach locking relay 5WSR; at armatures I2 and I3 opens points in the operating circuits of all of the R4 signals, thereby insuring that such opposing signals are at stop; and at the front contacts of these armatures closes points in the operating circuits of all of the LG signals. The relay L4HS also at contacts I99 opens, the pick-up circuit of relay ITS, but without eifect'at this time because of the previously established stick circuit through this relay.

The relay SWSR. in rel-easing, at contacts 56 opens a further point in the circuits of the R4 signals; at contacts I9I opens a point in the circuit of relay 5W, thereby locking switch 5 against operation; and at contacts 51 interrupts the stick and pick-up circuits of route locking relay IWSR. The relay IWSR, on releasing, at contacts i9 opens the control circuit of switch I and-opens a pair of contacts I99 included in the control circuit of switch 3, thereby effectively The relay IWSR. also, at contacts II now connects the positive terminal B to the winding 84 of signal L4A via contacts H5 of relay IESR, the back contact and armature 69 of relay R4HS, the neutral contacts H9 and 9 of relays IKR and BKR, respectively, the polar armature 93 of relay 3KR and its normal contact,the neutral contacts 94 of r'elayl'aKFt, armature I3 of relay L4HS and its front contact, the polar armature 83 of relay EKR and its normal contact, contacts I5 of stick relay ITS, and the Winding 84 of signal L4A to the negative terminal C. The signal L IA accordingly moves to its proceed indicating position and in so doing opens its contacts I01, thereby ,opening a second point in the pick-up and stick circuits of relay 5WSR. When the westbound train enters section 5T the relay 5TR, in releasing, at contacts 29I opens a second point in the control circuit of switch 5, and at contacts 89 closes a pointy in a pick-up circuit of relay 5WSR. The operator may now. release relay L4I-IS to return signal L IA- to stop by opening its circult at armature'l3 and at contacts II reclose the initially opened point in the pick-up circuit of relay 5WSR. The signal L4A in returning to stop position, at contacts I91 again completes the obvious pick-up circuit for relay 5WSR "including the contacts 89 of track relay 5TR. The relay 5WSR. thereupon picks up and at its armature 55 opens the circuit extending to time element relay 4TER before that relay can operate, and at its front contact reestablishes its stick circuit. The relay 5WSR also, at contacts 51 closes a point in the pick-up and stick circuits of relay IWSR, and at contacts I9I closes a point in the control circuit of switch 5. The previously mentioned contacts 29I of track relay 5TR, however, now prevent the control circuit for switch 5 being closed while the train remains in section 5T.

The signal MA is at this time employed in the same manner as are signals RAB and R40. It will, therefore, be apparent from the foregoing description that, should the operator delay releasing the relay L4HS to return signal L4A to stop, until after the train has cleared section 5T, the picking up of relay 5WSR will be brought about only through the medium of relay 4TER.

When the train enters section 3T the track relay 3TB. restores and at contacts 59 opens another point in the pick-up circuit of relay IWSR, and at contacts 290 also opens another point in the circuit of switch control relay 3W of switch 3.

When the train clears section 5T the track relay 5TH. again picks up and by closing contacts 29I returns the control of switch 5 to the operator. The relay 5TR also, at contacts 89 again opens the pick-up circuit of relay 5WSR. The relay 5TB also, at contacts 58 recloses a point in the pick-up circuit of relay IWSR, but since contacts 59 of relay 3TR are now open this circuit is not yet completed.

When the train enters section IT the relay ITR. releases and at contacts 29 opens another point in the circuit of the switch control relay IW thereby preventing movement of switch I while the train is in the section even with relay IWSR picked up.

When the train clears section 3T relay 3TR again picks up to again close contacts 290 in the control circuit of switch 3. Now, as soon as the train clears section IT, by passing on into section AIT or by movement over switch I, should that switch have been reversed prior to the entry of the train into the stretch, relay ITR at contacts I9 again completes the pick-up circuit of relay IWSR. Relay IWSR on picking up, recloses its stick circuit at contacts I8 and at contacts I! again disconnects the positive terminal B from the common portion of the operating circuits of the L signals.

In the foregoing description it was assumed that the operator released the relay L4HS after the train entered section 5T to put the signal L4A to stop. Since, with switch I in its normal position, relay INP at contacts I4 renders the operation of the track relay contacts II, I2 and I3 ineffective, it will be apparent that if the operator does not release relay L4HS the signal L4A will continue to indicate proceed.

If, however, the switch I is reversed before the operator picks up relay L4I-IS to clear signal L4A, contacts I4 of relay INP will be open and contacts I4I of relay IRP will be closed. Under these circumstances, when the train enters section 5T the circuit of relay ITS is interrupted by the opening of contacts I3 of the track relay 5TB, and subsequently by contacts I2 of relay 3TB and II of relay I'I'R. The relay ITS accordingly releases and at contacts I43 completes a shunt about contacts 89 of track relay 5TB, thereby enabling the operator to pick up relay 5WSR, and again obtain control of switch 5, without the delay which would otherwise be introduced by timing relay 4TER, should the oper- 'ator delay the release of relay L4HS until after contacts 89 have opened. The relay ITS at contacts I opens the circuit of winding 84 of signal L IA. The signal L4A accordingly automatically goes to its stop position. Under these circumopens the shunt from around contacts 89 of track relay 5TR, and at its contacts I5 again closes a point in the circuit of winding 84 of signal L4A. To again clear signal L4A for .a second train movement over the established route the operator again picks up relay L4I-IS whereupon the foregoing cycle of operations will be repeated.

It will now be assumed that the operator reverses the switch 5 as soon as the first westbound train entering the stretch has cleared section 5T and then again picks up relay L4HS to clear signal LAC to permit a train to enter the stretch over switch 5. With switch 5 reversed it will be apparent that its associated indication relay 5KR will have moved its polar armatures to their reverse position, that the associated normal indication repeating relay 5NP will be released, and that the reverse indication repeating relay 5RP will be picked up. The relay 5KR at its polar armature 83 and at its normal contact opens points in the circuit of winding 84 of signal L4A and at its reverse contact closes the circuit of winding 85 of signal L4G to clear such signal. It will be observed that, with switch 5 reversed, contacts I42 of relay 5NP will be open and therefore contacts 89 of track relay 5TB. are not shunted. The manner of picking up relay 5WSR. following the release of relay L4HS accordingly depends on the occupied or non-occupied condition of section 5T, in the same manner as when relay L4l-IS is released following the clearance of signal L4A with switch I at normal.

The usual approach or stick locking protection for westbound trains entering the stretch under clearance of signals L4A and L40 is provided. Since the operations are the same irrespective of which of the signals L IA or LlIC is cleared and returned to stop a description of the operation only of one of the two instances will be necessary. It will be assumed, as an example, that the operator clears signal LdA and then returns it to stop in the face of an approaching train by first picking up and then releasing relay L4HS. The relay L4I-IS, in releasing now, at contacts II extends positive potential from terminal B and through contacts of the L signals, all in stop position, to the time element relay 4TER via armature 55 of relay 5WSR. and its back contact and contacts III of relay IESR. If the train enters section 5T before the time element relay has had time to close its contacts 42 the relay 5TB. will, at its contacts 89, complete the pickup circuit of relay 5WSR, but the operator will now be prevented from operating the switch by the opening of contacts 29I of track relay 5TH.

If, on the other hand, the relay iTER closes its contacts 42 before the train enters section 5T, relay 5WSR will pick up, and since the contacts 29I of relay 5TR included in the control circuit of switch 5 are still closed, will enable the operator to change the position of the switch.

In case one of the L signals is cleared for an be moved by the operator.

approaching train and is then immediately returned to stop, the functioning of the time element relay ITER in delaying the pick-up of relay 5WSR, also prevents the operator from immediately clearing any R signal, as the common portion of the R. signal network is held open by contacts 55 of relay SWSR until such relay picks up.

It will now be assumed that the switch 3 has been reversed and that the operator picks up relay L4HS to clear signal LIB to enable a westbound train to enter the stretch at this point. As will be clear from the preceding description, with switch 3 reversed, its indication relay 3KR will have its polar armatures in engagement with their reverse contacts, the reverse indication relay 3NP is released, and relay 3RP is picked up. The relay 3KR therefore, at its polar armature 93, in moving to its reverse position, opens a common point in the circuits of windings 84 and 85 of signals LlA and L4G, respectively, and closes a point in the circuit of winding 82 of signal L43. The relay 3NP on releasing, at contacts 90 removes the relay 5WSR from control by track relay 5TH, while the relay 3RP in picking up places relay 5WSR under control of contacts 9| of track relay 3TR.

The relay L4HS, on picking up now, at contacts "I2 closes another point in the circuit of winding 82 of signal L4B, and at contacts 'II interrupts the stick circuit of relay 5WSR. The relay LdHS also at armature "I3 closes a point in the common portion of the operating circuits of signals MA and L4G, but without effect as these circuits remain open at armature 93 of relay 3KR, now in its reverse position. Relay EWSR, in releasing, opens the control circuit of switch 5 and the circuit of relay IWSR in the manner hereinbefore described. The relay I WSR, in releasing, opens the control circuits of switches I and 3 as hereinbefore also fully explained, and at its contacts I! now completes a circuit through winding 82 of signal L413. This circuit will be obvious in the light of the preceding descriptions. The signal L IB in changing to clear at contacts I08 opens a second point in the pick-up circuit of relay SWSR.

When the train enters section 3T, the track relay 3TB releases and at contacts 9I prepares a pick-up circuit for relay 5WSR, and as previously explained, opens a second point in the control circuit of switch 3. The operator may now release relay L IHS to return the signal MB to stop byinterrupting its circuit at contacts I2. The signal L4B in returning to stop again closes its contacts I08 thereby completing the prepared pick-up circuit for relay 5WSR directly, or through the medium of relay 4TER if the train has cleared section 3T. The picking up of this relay returns the control of switch 5 to the operator, but the open contacts 59 of track relay 3TB. prevents the closure of contacts 51 of relay 5WSR from completing the circuit of relay IWSR While the train remains in section 3. Since, as hereinbeiore explained, the relay IWSR has contacts I9 and I99 included in the I and 3 switch control circuits, neither of these switches can yet Furthermore, it will be observed that the pick-up circuit of relay IWSR includes contacts 10 of track relay ITR. It will, therefore, be apparent that before the relay IWSR can pick up and restore control of switches I and 3 to the operator that both track sections ST and IT must be unoccupied. The usual route'locking protection against movement of switch 3, after signal LAB has been cleared and returned to stop in the face of an approaching train, is provided. Under such circumstances the relay L4HS, in restoring, at contacts ll extends positive potential from terminal B and through contacts of the L signals, all in stop position, to the time element relay 4TER, Via armature 55 of relay 5WSR and its back contact, contacts Ill of relay IESR to the winding of time element relay 4TER and to the negative terminal C.

If the train enters section 3T before the time element relay has had time to close its contacts 42 the relay 3TB. will, at contacts 9|, complete the pick-up circuit of relay 5WSR, and at contacts 59 open a point in the pick-up circuit of relay IWSR. Therefore, on the subsequent picking up of relay SWSR the closure of contacts 51 thereof will be inefiective to pick up relay IWSR. Accordingly, the operator is under these circumstances prevented from operating switch 3 by the open contacts I39 of relay IWSR.

If, on the other hand, the relay 4'IER closes its contacts 42 before the train enters section 3T, relay iWSR will pick up consequent to the closure of contacts 51 of relay SWSR. Since at this time contacts 290 of track relay 3TR are still closed, the operator is enabled to change the position of the switch.

From the foregoing, it will be seen that I have succeeded in the development of circuits, ap plicable to a combination of manual, semi-auto matic stick, as well as semi-automatic non-stick, signals and that: (1) these circuits exactly check that approach and route locking are effective before a signal can be cleared; (2) that the operator need not restore the control relay while the train is in the detector section; (3) that these circuits further, to a certain extent, check themselves should improper operation occur due to the presence of stray current; (4) and that they further include arrangements for effectively guarding against the improper release of approach and route locking consequent to a temporary loss of shunt in an approach section.

Having described my invention, what I consider to be new and desire to cover by Letters Patent will be further brought out in the claims hereunto appended.

1. In a signaling system, a signal displaying one indication when deenergized and another indication when energized, a relay energized over a circuit including contacts of said signal closed when the signal is deenergized, contacts on said relay normally holding the circuit for energizing said signal open, a second relay having a pick-up circuit in multiple with the energizing circuit of said signal, but excluding contacts of said first relay, a third relay having contacts included in the circuit of said first relay and being operable to release said first relay to complete circuits through said signal and said second relay respectively, the contacts on said signal opening a second point in the circuit of said first relay when the signal is cleared, and contacts closed by said second relay in shunt of those opened by said third relay effective to again immediately pick up said first relay in case the opening of the contacts of said signal has failed to remove operating potential from the circuit for said first relay.

2. In a traflic control system, a stretch of track, a signal for governing traflic entering such stretch, an approach locking relay for the stretch, a signal control relay, a second relay normally energized over a circuit including contacts of said signal control relay whereby operation of said signal control relay to clear said signal effects the release of said normally energized relay, contacts opened by the release of said second relay to effect the release of said approach locking relay and the closing of a point in a circuit employed to clear said signal, a third relay, other contacts closed by operation of said control relay completing circuits through said signal to clear it and through said third relay, contacts on said signal operated consequent to its clearance to open a second point in the operating circuit of said normally energized relay, and contacts on said third relay subsequently closed to place a shunt about the contacts in the circuit of the normally energized relay opened by the picking up of said signal control relay whereby if a stray operating potential is encountered by any portion of the circuit extending between the open contacts of the cleared signal and the contacts of said third relay the normally energized relay will again pick up and interrupt the circuit of said signal.

3. In a railway signaling system, a stretch of railway track divided into a plurality of sections each equipped with a track relay, a railway switch adjoining one section of the track, an approach locking relay for said switch; a circuit for controlling the movement of said switch including contacts of one of said track relays and of said approach locking relay, respectively; a signal for governing traffic entering the switch equipped section of said stretch, a manually controlled relay having means under its control for releasing said approach locking relay, a circuit for clearing said signal completed by the release of said approach locking relay and including contacts subsequently opened by said manually controlled relay to permit the return of said signal to stop prior to the entry of a train into the switch equipped section, and means delaying the picking up of the approach locking relay for a definite'flxed period of time after said manually controlled relay has been released if the track relay of the section to the rear of said signal has been released by a train therein even should such relay again pick up due to a subsequent loss of track shunt while the train is in such section.

4. In combination with a stretch of track divided into a plurality of insulated track sections each equipped with a track relay and wherein such stretch employs an approach locking relay for preventing the movement of a switch after an operation is performed to clear a signal governing traflic into the section of the stretch in which the switch is located until such protection is afforded by the release of the track relay upon' actual entrance of a train into such section of the stretch, a second relay having a pick-up circuit opened by the release of the approach locking relay; a stick circuit for said second relay opened by the track relay of the section preceding the one with which a switch is associated, when a train enters such section; and contacts included in the pick-up circuit of the approach locking relay opened by the restoration of said second relay to prevent the picking up of the approach locking relay prematurely in case the track relay of such approach section again picks up while the train is in such section.

5. In a traffic control system, a stretch of track including an adjoining track switch and being divided up into a plurality of sections including a detector section in which such switch is included and an adjoining approach section, an approach locking relay included in a normally closed circuit and having contacts normally closed to enable the movement of said switch, a signal at the junction of said track sections for governing the movement of trains entering said approach section in a direction toward said detector section, means for opening the circuit of said approach locking relay and for clearing said signal in the order named; a second relay having pick-up and stick circuits which are normally closed and the pick-up circuit of which is opened by the release of said approach locking relay and also having normally closed contacts included in the pick-up circuit of said approach locking relay; and means controlled by a train entering said approach sectionfor breaking the stick circuit of said second relay to thereby insure that said approach locking relay cannot there- I after pick up until the train'has cleared said approach section.

6. In combination, asection of-railway track containing a switch, an approach'locking'relay, means for preventing operation of said switch unless said relay is energized, an auxiliary relay having a pick-up circuit includingfront contacts of said approach locking relay, a second section of track, a track circuit for said second section including a track relay connected across rails thereof, a stick circuit for said auxiliary relay-including front-contacts of the track relay of said second section, and a pick-up circuit for said approach locking relay including front contacts of said auxiliary relay.

'7. In combination with a stretch oftrack divided into a plurality of electrically-insulated sections and also having associated switches over which trains may be'routed over divergent paths, a signal at the entrance of the stretch for governing traffic therethrough, a first relay operable to clear said signal, a second relay normally energized over a circuit including contacts of said signal and of said first relay respectively, an approach locking relay for one of said sections, position indication relays for the' respective switches in the stretch, track relays for the respective sections of the stretch, a third relay, an energizing circuit for said third relay including a branch circuit for clearing said signal, said branch circuit including contacts of said track and approach locking relays, said first and second relays, as well as certain of said indication relays to enable clearance of said signal only when said switches are in a particular position and when said sections are all unoccupied, the track relay of the first section in advance of the signal serving to insure the return of said signal to stop when the train enters the stretch, contacts on said third relay enabling the reenergization of said second relay in response to the return of said signal to stop, and means including said third relay for again clearing said signal as soon as the train leaves the stretch in certain instances.

8. In a railway signaling system for a stretch of track, associated switches adjoining the main track of the stretch via which a train entering the stretch may be routed, signals at the entrance to the stretch for directing trafiic over the various routes, remotely controlled means operated to effect the clearance of, one of said signals to permit the passage of a train through the stretch over a selected route, a normally energized approach locking relay deenergized consequent to the actuation of said means to lock the set route until the train has entered the stretch, other means for thereafter locking the route while the train remains in the stretch, means operated consequent to the entry of the train into the stretch to eifect the restoration of the cleared signal to stop, and means for also automatically effecting the deenergization of said approach locking relay to enable the automatic clearance of such signal for the set route as the train passes out of the stretch providing the re- -motely controlled means is still in its operated condition.

9. In combination with a stretch of track divided into a plurality of insulated track sections each provided with a track relay and certain sections of which have railway track switches. associated therewith, a group of signals at one end of the stretch; operator controlled means for clearing one of said signals, the signal cleared being dependent on the position of a given one of said switches at the time such means is operated; means controlled by the track relay of the first section of the stretch as it becomes occupied to enable a given cleared signal to return to stop only if a given switch in the exit section of the stretch occupies a position other than a given position, and means controlled by the track relays of the subsequent sections after said first section of the stretch for positively preventing the clearance of such signal while any of such sections are occupied.

10. In a traffic control system applied to a stretch of track having associated switches via' which traffic may pass over difierent routes and over which traflic normally moves in one direction only, a signal at the exit end of said stretch for governing the movement of traflic against the normal direction, means for manually controlling said signal for traffic movement over one route of the stretch and for then manually returning said signal to stop, means for causing said signal to function as a semi-automatic stick signal when the same is cleared for a traffic movement over an alternative route over the stretch, another signal at the entrance to the stretch for governing traffic over the stretch in the normal direction, means operated to clear said latter signal, means operated in the course of the clearance of said latter signal for causing it to automatically return to clear indicating position after the train has passed through the stretch, and means for causingsaid signal to remain in its stop indicating position after the train has passed through the stretch in case the means operated to clear it has been restored prior to the exit of the train from the stretch.

11. In a signaling system, a normally deenergized signal, a signal repeating relay normally energized when said signal is in its normal position, a signal control relay operable at will and having normally closed contacts included in the circuit of said signal repeating relay whereby! operation of said control relay effects the release of said signal repeating relay, a slow to operate relay having normally open contacts connected in multiple with the normally closed contacts of said signal control relay for preparing a pickup circuit for said repeating relay which is independent of said control relay, circuits for energizing said signal and for picking up said slow to operate relay closed by means jointly controlled by said control relay in operating and by said repeating relay in releasing, means actuated by said signal when energized to open a second point in the circuit of said repeating relay before said slow to operate relay closes its contacts to prevent the immediate picking up of said signal repeating relay, and means for subsequently temporarily interrupting the circuit of said signal to deenergize it to close the new circuit prepared for said repeating relay to pick it up and thereby hold the circuit of said signal open after said temporary means has ceased to function.

12. In a signaling system, a normally deenergized signal, a signal repeating relay normally energized when said signal is in its normal position, a signal control relay operable at will and having normally closed contacts included in the circuit of said signal repeating relay whereby operation of said control relay efiects the release of said signal repeating relay, a slow to operate relay having normally open contacts connected in multiple with the normally closed contacts of said signal control relay for preparing a pick-up circuit for said repeating relay which is independent of said control relay, circuits for energizlng said signal and for picking up said slow to operate relay closed by means jointly controlled by said control relay in operating and by said repeating relay in releasing, means actuated by said signal when energized to open a second point in the circuit of said repeating relay before said slow to operate relay closes its contacts to prevent the immediate picking up of said signal repeatingrelay, means for subsequently temporarily interrupting the circuit of said signal whereupon it will become deenergized to close the new circuit prepared for said repeating relay to pick it up and thereby hold the circuit of said signal open after said temporary means has ceased to function, and means for thereafter automatically releasing said slow to operate relay to again effect the release of said repeating relay andthe consequent energization of said signal.

13. In a trafiic control system for a stretch of track having a plurality of track switches associated therewith and which is divided up into a plurality of track relay equipped sections, a signal at the entrance to the stretch for governing trafiic therethrough, a remotely controlled signal control relay for clearing said signal, an approach locking relay for preventing the operation of one of said switches after the signal has been cleared, route locking relays under control of said approach locking relay for preventing the remainder of said switches being operated after said signal has been cleared, a relay normally energized over a circuit including contacts of said signal control relay and released thereby when said signal control relay is operated to clear said sgnal, contacts on said normally energized relay opened by its release to thereby release said approach locking relay to effect the locking of 'all switches in the stretch, and a circuit for clearing said signal completed only after all of said switches have been locked and'all track sections of the stretch are unoccupied as evidenced by the picked up condition of their associated track relays.

14.111 combination, two sections of railway track, a signal at the junctions of said sections for governing traffic through one of them, a circuit for clearing said signal when closed, an approach locking relay having back contacts included in said circuit, a stick circuit for holding said relay energized, means operated to close one point in said first circuit and to open said stick circuit to enable said approach locking relay to complete the closure of said first circuit, said means being again operable to again open the specified one point in said first circuit to immediately return said signal to stop, means responsive to the return of such signal to stop when said other section is unoccupied to immediately complete a pick-up circuit for said approach locking relay, means responsive to the occupancy of said other section when such signal returns to stop for completing a pick-up circuit for said approach locking relay a fixed interval of time after the return of said signal to stop, and another signal for governing trafiic through said sections having a clearance circuit including front contacts of said approach locking relay.

15. In combination with a stretch of track divided into a plurality of insulated track sections each provided with a track relay and certain sections of which have railway track switches associated therewith, a semi-automatic non-stick signal for governing the movement of traffic into the stretch from one end, a semi-automatic stick signal for governing traflic entering the stretch from the other end, normally energized approach and route locking relays effective when deenergized to prevent movement of their associated switches, operator controlled means for releasing certain of said relays and for clearing one of said signals to enable a train to enter the stretch, and means rendered effective by the release of said operator controlled means to immediately energize the approach locking relay of the first switch equipped section of the stretch encountered irrespective of the location of the train in the stretch.

16. In a signaling system, a signal, a relay energized over a circuit including contacts of said signal closed when the signal is deenergized, contacts on said relay normally holding the circuit for energizing said signal open, a second relay having a pick-up circuit closed when the energizing circuit for said signal is closed, a third relay operable to release said first relay to complete circuits through said signal and said second relay respectively, the contacts on said signal opening a second point in the circuit of said first relay when the signal is energized and before said second relay has picked up, and contacts closed by said second relay eifective to again pick up said first relay in case the opening of the contacts of said signal has failed to remove operating potential from the circuit of said first relay.

17. In combination, a stretch of railway track, a signal for directing traffic into the stretch, a repeating relay for said signal having a circuit including contacts of said signal, a signal control relay having contacts also included in said circult and operated to effect the release of said relay, a circuit for clearing said signal including back contacts of said signal repeating relay and front contacts of said signal control relay respectively, another relay having a circuit closed by said signal control relay when picked up and having contacts closed around the contacts opened by the picking up of said signal control relay after the signal has had time to clear whereby the release of said signal repeating relay and the consequent clearance of said signal will be annulled in case there is stray operating current applied to said circuit at any point between the signal control relay contacts and the contacts of the signal itself.

18. In combination with a stretch of railway track provided with a railway switch, a signal for governing trafjc entering the stretch, a signal repeating relay for said signal, an approach looking relay effective when deenergized to prevent movement of the associated switch and itself having a stick circuit including front contacts of said signal repeating relay, a signal control relay for clearing said signal having contacts included in a circuit for said signal repeating relay, a slow acting relay having an energizing circuit including contacts of said signal control relay, and a pick-up circuit for said approach locking relay including front contacts of said slow acting relay.

19. In combination with a stretch of railway track having a railway switch associated therewith, a normally deenergized signal, a signal repeating relay-energized when said signal is in its normal position, an approach locking relay for said switch energized over a stick circuit including front contacts of said signal repeating relay, a signal control relay operable at will and having normally closed contacts included in the circuit of said signalrepeating relay whereby operation of said signal control relay effects the release of said signal repeating relay, a slow acting relay, a circuit for energizing said slow acting relay including front contacts of said signal control relay; a circuit for energizing said signal closed jointly by said control, approach locking and repeating relays; and a pick-up circuit for said approach locking relay including front contacts of said slow acting and signal repeating relays respectively.

20. In combination with a stretch of railway track having a switch associated therewith, a signal for directing traflic into the stretch, a signal control relay operated to clear said signal and released to return said signal to stop, an approach locking relay for preventing movement of the switch after said signal has been cleared, a slow acting relay operated through the medium of said signal control relay when the latter relay is operated, a pick-up circuit for said approach locking relay including front contacts of said slow acting relay, and a stick circuit for said approach locking relay including contacts closed only when said signal is at stop.

21. In a signaling system, a signal, a normally energized signal repeating relay, a signal control relay operable at will and having normally closed contacts included in the circuit for said signal repeating relay whereby operation of said control relay effects the release of said signal repeating relay, a circuit for clearing said signal under the joint control of said signal control and repeating relays respectively, a slow acting relay having an energizing circuit closed by said signal control relay when said control relay is operated to clear said signal, means actuated by said signal when cleared to open a second point in the circuit for said repeating relay before said slow acting relay picks up, means for subsequently opening the circuit for said signal, and a new circuit for said repeating relay prepared by said slow acting relay and completed by said signal after'the circuit for said signal is opened.

22, In combination, a section of railway track including a switch, a signal for governing traffic movements in a given direction over said switch, a first and a second approach section of said railway track over which traffic movements in said given direction approach said signal, an approach locking stick relay, an auxiliary stick relay, a pick-up circuit for said approach locking relay controlled by a front contact of said auxiliary relay and closed only if said first approach section is unoccupied, a second pick-up circuit for said approach locking relay which is normally open but which is at times closed independently of traffic conditions in either of said approach sections, a stick circuit for said approach locking relay closed if said signal is controlled to indicate stop, a pick-up circuit for said auxiliary stick relay controlled by a front contact of said approach looking relay, a stick circuit for said auxiliary stick relay closed only if said second approach section is unoccupied, and means controlled in part by said approach locking relay for controlling operations of said switch if said approach locking relay is energized.-

23. In combination, a section of railway track including a switch, a signal for governing tralfic movements in a given direction over said switch, an approach section of said railway track over which traffic movements in said given direction approach said signal, an, approach locking stick relay, an auxiliary stick relay, a pick-up circuit for said approach locking relay controlled by a front contact of said auxiliary relay, a second pick-up circuit for said approach locking relay which is at times closed independently of trafiic conditions in said approach section, a stick circult for said approach locking relay closed if said signal is controlled to indicate stop, a pick-up circuit for said auxiliary stick relay controlled by a front contact of said approach locking relay, a stick circuit for said auxiliary stick relay closed only if said approach section is unoccupied, and means controlled in part by said approach looking relay for controlling operations of said switch if said approach locking relay is energized.

24. In combination, a stretch of railway track including a switch, a signal for governing traffic movements in a given direction over said switch, an approach locking stick relay, an auxiliary stick relay, a pick-up and a stick circuit for said auxiliary stick relay one of which is controlled by a front contact of said approach locking stick relay and the other of which is controlled by trafiic conditions and is closed only if said stretch of track is unoccupied for a given distance in the rear of said signal, a pick-up and a stick circuit for said approach locking stick relay one of which is controlled by trafiic conditions which are independent of traflic movements approaching said signal in said given direction and the other of which is closed only'if said signal is controlled to indicate stop, a second pick-up circuit for said approach locking stick relay controlled by a front contact of said auxiliary stick relay whereby said second pick-up circuit will not be closed due to a loss of shunt of the track in the rear of said signal while a train is approaching within said given distance in the rear of said signal, and means controlled in part by said approach locking relay for controlling operations of said switch if said approach locking relay is energized.

. 25. In combination, a stretch of railway track, a signal for governing trailic movements over said stretch, a signal control relay, a signal repeating relay, an energizing circuit for said signal repeating relay controlled by said signal and by said signal control relay and closed only if said signal indicates stop and if said signal control relay is decnergized, a circuit for clearing said signal controlled by said signal control relay and by said signal repeating relay and energized only if said signal control relay is energized and said signal repeating relay is deenergized, an auxiliary relay controlled by said signal control relay in the energized condition and constructed to close its front contacts after said signal has left its stop condition, and a branch path closed by a front contact of said auxiliary relay around the portion of the energizing circuit for said signal repeating relay which is controlled by said signal control relay.

26. In combination, a stretch of railway track, a signal for governing traffic movements over said stretch, a signal control relay, a signal repeating relay, an energizing circuit for said signal repeating relay including a contact closed by said signal when said signal indicates stop and also including a back contact of said signal control relay, a circuit for clearing said signal including a front contact of said signal control relay and a back contact of said signal repeating relay, a slow acting auxiliary relay, a circuit including a front contact of said signal control relay for energizing said auxiliary relay, and a branch path including a front contact of said auxiliary relay connected around the back contact of said signal control relay in the energizing circuit for said signal repeating relay.

27. In combination, a stretch of railway track containing a switch, a signal for governing traflic movements over said switch, a manually controllable device, and means controlled by said device for clearing said signal only under clear track conditions in said stretch if said switch occupies a given position and for clearing said signal independently of said track conditions in said stretch if said switch occupies a second given position.

28. In combination, a stretch of railway track containing a switch, a track circuit for said stretch including a track relay, a signal for governing traflic movements over said switch, a manually controllable device, and means controlled by said manually controllable device and by said switch and said track relay for clearing said signal when said switch occupies a given position only if said track relay is energized and for clearing said signal when said switch occupies a difierent position independently of the condition of said track relay.

EARL M. ALLEN. 

